Abrasion resisting tube



Nov. 6, 1934. w. E. BOYLE 1,979,444

ABRASION RESISTING TUBE Filed July 50, 1932 INVENTOR MZZiamE u qyATTORNEYS Patented Nov. 6, 1934 UNITED STATES ABRASION RESISTING TUBEWilliam Edward Boyle, Madison, N. J., assignor to Spaulding Fibre Co.Inc., Tonawanda, N. Y., a corporation of New Hampshire Application July30, 1932, Serial No. 626,977

4 Claims.

This invention relates to protective sleeves or tubes which are adaptedto be applied to overhead conductors to protect them against abrasionand other mechanical injury and to pro- 5 vide additional insulation atthe points of application, such sleeves or tubes having particularutility when employed in connection with overhead distribution systemsin which certain of the conductors are installed in close proximity totrees.

Swaying tree branches often cause service interruptions, usually byintermittent grounding of the conductors in their vicinity. As ordinaryweather-proof wire will not withstand for long the abrasive action ofswaying tree limbs, specially covered wire known to the trade as treewire has been proposed, the said wire having a heavy rubber insulationreinforced with abrasive-resisting tapes and braids. It is the practiceto further reinforce this kind of wire, as well as the ordinaryweather-proof wire referred to, with sleeves made of wood, fibre, or thelike, whereby to provide additional protection at the points where theconductor may come into contact with the tree limbs.

One object of my invention is a sleeve or tube which is adapted toprovide adequate reinforcement of a relatively permanent nature toeither bare or insulated conductors.

A further object is to provide a sleeve or tube which has highdielectric and abrasion resisting characteristics. 7

A still further object is to provide a sleeve or tube which isapplicable to conductors of various diameters, this object contemplatinga sleeve or tube which, when it is applied to a conductor, automaticallyadjusts itself to the size of the conductor.

A still further object is to provide a sleeve or tube which may beapplied with facility.

A still further object is to provide a sleeve or tube which is light inweight and which is so designed that the diameter of the conductor willnot be increased to an objectionable degree at the point where it isapplied.

The sleeve or tube is formed from a base material which is impregnatedor coated with a binder. The base material is preferably of a fibrouscharacter and may, for example, be of duck, jute, paper or the like. Thebinder is preferably a synthetic resin such as, for example, Bakelite orthe like and it may, if desired, include a filler such as bituminousmatter or a shelf-lubricant such as graphite.

In the manufacture of the sleeve or tube, as-

suming for purposes of illustration that the base material is duck andthe binder a 40 to 50 percent phenol-formaldehyde resin, the duck may bepassed through a bath of the resin or otherwise suitably coated with it.The resin is first 0 dried to the proper stage. Heat and pressure arethen applied to the sheet to cure the resin to the extent desired. Thesheet is then rolled into a tube while hot and held in this shape whileit cools. As the sheet cools the binder hardens and sets, therebycausing theyarious convolutions. of the tube to resiliently retain theirshape when the tube is released. The tube can be unrolled or opened toenable its application to a conductor. When released the variousconvolutions thereof automatically contract toward their original shape,the tube preferably being so formed that the inner convolution engagesthe conductor as it approaches its original shape.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a perspective view of a finished tube stretched out in theform of a sheet.

Figure 2 is a plan view of a modified form of tube which is alsostretched out in the form of a sheet.

Figure 3 is a perspective view of a tube rolled to final shape, the tubebeing formed from a sheet of the kind shown in Figure 1.

The shaded portion A of the sheet shown in Figure 1 is that part whichprovides the inner convolution of the tube, that is to say theconvolution which lies adjacent the conductor. Preferably the surface ofthis part of the tube is rough so that it will engage the conductor andprevent the tube from slipping along the conductor after it has beenarranged in the desired position. After the binder is dried, preparatoryto the operation in which it is cured, the entire surface of the sheet 9is rough. In the curing operation that part of the surface which istreated becomes hard and smooth. The desired surface characteristics ofthe zone A, therefore, may be obtained by so arranging the sheet withreference to the dies of the curing equipment that the said zone escapestreatment. The treatment of the sheet in the manner described is notobjectionable as the zone in which the binder is cured is of such alength as to afford the desired dielectric and abrasion-resistingqualities.

In the embodiment illustrated in Figure 2 the binder is cured throughoutthe entire sheet. In

this embodiment, therefore, the inner convolution of the tube is similarin physical characteristics to the outer convolutions.

The tube described has high dielectric properties. Owing to the highresistance which it offers to abrasion, its frequent replacement isavoided. Preferably it fits closely around the conductor, therebypreventing the formation of air and water pockets. The factor of safetyagainst electively low ice load. The tube is very light in'.

weight as compared to other protectors. It can be made any desiredlength and diameter. It

can be readily applied at the desired point, without necessitating thecutting of the wire, by a simto water,

ple unrolling and re-rolling operation. No bolts, screws'or clips arerequired to secure it in position. It is applicable to ordinary bare orweatherproof wire as well as to so-called tree wire.

Maintenance costs are low as thetube is resistant chemicals, heat, oil,actinic rays and fire. c

As pointed out heretofore, the tube tends to retain its form and hencewhen it is unrolled during its application to a conductor andthenreleased,

it automatically contracts itself upon the conduc tor as it returns toits original form or as close to such form as the conductor will permit.During such contraction the inner convolution of the tube engages theconductor and owing to the roughened condition thereof the guard will beheld from slipping along it, it being understood in this connection thatthe securement of the tube against slipping may be effected in anysuitable manner. In curing the sheet from which the guard is formed thesheet is provided with a hard, smooth surface. Thus, the binder not onlycauses the tube to retain a prescribed shape but it also provides thesheet with a surface which is highly resistive to abrasion, thesmoothness of the surface reducing the friction between the tube and. anabrading object to a- The tube, therefore, is capable of withstandingthe rubbing action of a contacting object over long periods of time. 7

Having thus described the invention, what is claimed, is:

1. An abrasion resisting guard comprising a fabric sheet impregnatedwith a binder which consistsof a1 phenol-formaldehyde condensationproduct, said sheet being rolled to provide a tube, said binder causingthe tube to resiliently retain its shape, whereby it can be unrolled toenable its application and whereby, when released, it will return to itsoriginal shape.

2. An abrasion resisting guard comprising a fabric sheet. impregnatedwith a binder which consists of a phenol-formaldehyde condensation.product, said sheet being spirally wound to provide a tube, said bindercausing the tube to resiliently retain its shape, whereby it can beunrolled to enable its application and whereby, when released, it willreturn to its original shape.

8. An abrasion resisting guard comprising a fabric sheet impregnatedwith a binder which consists of a phenol-formaldehyde condensationproduct, said sheet being spirally wound to provides, tube, said bindercausing the tube to resiliently retain its shape, whereby it can beunrolled to enable its application and whereby,

when released, it will return to its original shape, the innerconvolution of said tube being adapted to engage the object upon whichthe guard is arranged andhold the said guard against slipping from theposition in which it is arranged.

4. An abrasion resisting guard for a conductor comprising a sheet ofduck impregnated with a binder which consists of a phenol-formaldehydecondensation product, said sheet being rolled to provide a tube, saidbinder causing the tube to resiliently retain its shape, wherebyit canbe unrolled to enable its application and whereby, when released, itwill contract around the said conductor.

WILLIAM EDWARD BOYLE.

